In the proposal, we will elucidate the mechanisms, and subsequently the therapeutic approach to human ovarian autoimmune disease, a known cause of premature ovarian failure. To do this, we will use a new model of murine autoimmune oophoritis which we have developed, by immunizing mice with a synthetic 13-me peptide. ZP3330-342 from ZP3 of the murine zona pellucida. With T cell clones that can adoptively transfer autoimmune oophoritis, we will map the pathogenic epitopes in the ZP3 peptide and determine the critical cytokines responsible for the ovarian disease. The model also will be exploited to determine the feasibility of a contraceptive vaccine based on ZP3. The unique ZP3330-342 peptide contains both B cell (ZP3336-342) and T cell epitopes that readily induce antibody and T cell responses to ZP3. Antibody to the ZP3. Antibody to the ZP3 peptide results in reversible infertility, whereas the ZP3- specific T cells cause autoimmune oophoritis and ovarian destruction. Although an immunogen that induces an antibody response without eliciting a concomitant T cell response to ZP3 will likely be a safe ZP3 vaccine, we need first to show that such an antibody per se does not cause autoimmune oophoritis. Our strategy in investigating the critical role of antibody in autoimmune oophoritis will be to synthesize immunogens that contain the B cell epitope of ZP3, coupled to either a foreign antigen or a peptide capable of stimulating a strong T cell response. When the immunogen has been shown not to stimulate a T cell response to ZP3, we will study it for induction of: 10 infertility and reversal, 2) abnormal ovarian response to gonadotrophin and 3) oophoritis in female (C57BL/6xA/J)F1(B6AF1)mice. Our second approach will involve the transfer of saturating quantities of antibodies to ZP3 into normal female B6AF1 mice and study their fertility, ovarian function and ovarian pathology. We will investigate two kinds of antibodies that react with the native determinants of ZP3: 1) monoclonal antibodies to the B cell epitope(s) of ZP3330-342, 2) monoclonal antibodies to determinants of ZP3 outside the ZP3 outside the ZP3 330-342 peptide. The second group of antibodies will be produced by normal female B6AF1 mice immunized with the ZP3 330-339 peptide which lacks an intact B cell epitope. Although the ZP3 330-339 peptide does not elicit an antibody response to ZP3330- 342, it induces a T cell response to ZP3330-339 and autoimmune oophoritis. Remarkable, we have accrued evidence that the endogenous ovarian antigens from the injured ovaries in these mice stimulate an antibody response to the ZP3 determinants outside the peptide ZP3 330- 342, and such antibodies react with the zone pellucida in vivo. Because of the important implications that the new phenomenon of "antibody amplification' has on autoimmune oophoritis and autoimmunity in general, we will investigate the structure of the ZP3 determinants recognized by the amplified antibodies, and the biological significance of the "antibody amplification" phenomenon.